CN113173807A

CN113173807A - Method for treating domestic sludge by using earthworms

Info

Publication number: CN113173807A
Application number: CN202110643240.3A
Authority: CN
Inventors: 冯良山; 杨宁; 赵凤艳; 李开宇; 李颖; 孙翔龙
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-06-09
Filing date: 2021-06-09
Publication date: 2021-07-27
Anticipated expiration: 2041-06-09
Also published as: CN113173807B

Abstract

The invention discloses a method for treating domestic sludge by using earthworms, which belongs to the technical field of sludge treatment and comprises the following steps: adding wormwood into the domestic sludge to obtain a material A, then adding earthworm seedlings, carrying out vibration treatment, trapping and collecting earthworms after the treatment is finished, and adding straws and a zymophyte agent into a material B obtained by treating the earthworms for fermentation; according to the invention, the fresh degree of the biological sludge is kept by adding the wormwood, the earthworm treatment efficiency is improved, and then fermentation treatment is carried out, so that the components in the domestic sludge can be fully decomposed; the invention adds vibration treatment during fermentation treatment, so that more oxygen is blended into the sludge, thereby improving the thickness of the sludge treated at a time and improving the sludge treatment efficiency; after the domestic sludge is treated by the method, the domestic sludge meets the standard of organic fertilizers or biological organic fertilizers, can be directly used as the organic fertilizers or the biological organic fertilizers, has high fertilizer efficiency, and can obviously improve the crop yield.

Description

Method for treating domestic sludge by using earthworms

Technical Field

The invention belongs to the technical field of sludge treatment, and particularly relates to a method for treating domestic sludge by using earthworms.

Background

Along with the improvement of the urbanization degree and the expansion of the urban scale, the yield of the urban domestic sludge is increased day by day, the components in the urban domestic sludge are complex, the urban domestic sludge contains a large amount of organic matters and pathogenic bacteria, and the urban domestic sludge is rich in N, P, K and heavy metal elements, so that serious harm can be caused to water, soil and the like if the urban domestic sludge is not effectively treated, and the health of people can be indirectly influenced.

The domestic sludge is treated by adopting the treatment modes such as incineration, landfill and the like, so that not only is the treatment cost extremely high, but also the pollution problem cannot be fundamentally solved by the treatment modes, secondary pollution is easily caused to the environment, and other secondary pollution such as harmful gas, dust pollution and the like is treated if the calorific value of the direct incineration of the sludge is too low; the direct landfill of the sludge has the problems of difficult compaction and difficult natural fermentation, the land reuse of the landfill is directly influenced, and the sludge buried underground is a potential threat to the environment.

At present, the technology of treating urban domestic sludge by earthworms has been researched and used relatively, compared with the traditional treatment modes of incineration, landfill and the like, the treatment method of treating the domestic sludge by earthworms has low cost, and the excrement generated after the earthworms swallow the sludge can be used as organic fertilizer, so that the environment is not polluted secondarily, and higher economic benefit can be generated. However, since earthworms need to treat sludge under aerobic environment, the thickness of sludge needs to be controlled within 15 cm when using earthworms to treat domestic sludge, so that the amount of sludge treated each time is limited, and the efficiency of sludge treatment is greatly reduced. Therefore, it is required to develop a method for treating domestic sludge with high efficiency using earthworms.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a method for treating domestic sludge by using earthworms, so as to improve the treatment efficiency of the earthworms on the domestic sludge.

In order to achieve the purpose, the invention provides the following technical scheme:

the invention provides a method for treating domestic sludge by using earthworms, which comprises the following steps:

(1) adding wormwood into the domestic sludge to obtain a material A;

(2) and (2) putting earthworm seedlings into the material A obtained in the step (1), performing vibration treatment, trapping and collecting earthworms after treatment, and adding straws and fermentation inoculum into the material B obtained by earthworm treatment for fermentation.

Preferably, the addition amount of the wormwood in the step (1) is 0.5 percent of the weight of the domestic sludge

Preferably, before the earthworm seedlings are put into the material A in the step (2), the water content of the material A is adjusted to 65-70 wt%.

Preferably, 8000-10000 earthworm seedlings are put into each ton of the material A in the step (2).

Preferably, the vibration treatment in the step (2) is specifically: and (3) carrying out intermittent vibration treatment, wherein the vibration is carried out for 0.5 hour every 2-3 hours, and the vibration frequency is 10-15 Hz.

Preferably, the thickness of the material A in the step (2) is 25-30 cm.

Preferably, in the sludge treatment process of the earthworms in the step (2), the temperature is 20-25 ℃, and the treatment time is 10-15 days.

Preferably, the earthworm seedlings in the step (2) are Taiping II and/or Chizieisheng.

Preferably, the adding amount of the straws in the step (2) is 15-20% of the weight of the material B, and then urea is added to adjust the carbon-nitrogen ratio to be 20-25.

Preferably, the fermentation microbial agent in the step (2) is composed of bacillus natto, cellulose decomposition bacteria, bacillus megaterium, saccharomycetes and bacillus licheniformis according to the mass ratio of (1.5-2) to (1-2) to (2-3); the number of effective viable bacteria in the fermentation inoculum is more than or equal to 100 hundred million/g; the mass ratio of the fermentation inoculum to the material B is (1-2) to 1000; the fermentation time is 7-10 days.

Compared with the prior art, the invention has the following beneficial effects:

according to the invention, the wormwood is added into the domestic sludge, so that the domestic sludge can be kept fresh, and the earthworm foraging utilization is facilitated; meanwhile, the vibration treatment is carried out, and more oxygen can be blended into the sludge in the vibration process, so that the thickness of the sludge treated in one time can be improved, and the sludge treatment efficiency is improved;

according to the invention, on the basis of sludge treatment by earthworms, straw carbon sources and fermentation bacteria agents are further supplemented for fermentation treatment, so that sludge can be fully decomposed;

after the domestic sludge is treated by the method, the heavy metal content is greatly reduced, the domestic sludge meets the standards of organic fertilizers and biological organic fertilizers, can be directly used as the organic fertilizers and the biological organic fertilizers, has high fertilizer efficiency, and can obviously improve the crop yield.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

In the following examples, the contents of heavy metals cadmium, lead, chromium, mercury and arsenic (unit: mg/kg) in the dried domestic sludge are: cadmium: 7.2, lead: 63.5, chromium: 120.2, mercury: 5.1, arsenic: 20.4.

example 1

(1) Adding wormwood into the domestic sludge according to the weight ratio of 100: 0.5, and uniformly mixing to obtain a material A; adjusting the water content of the sludge to 70 wt%, laying the sludge on a vibration table, wherein the laying thickness is 30cm, then throwing 10000 earthworm seedlings into each ton of material A to treat the sludge, wherein the earthworm seedlings consist of Taiping II and Chizihessian in a quantity ratio of 1: 1, intermittently vibrating the vibration table in the treatment process, the vibration frequency is 15Hz, vibrating for 0.5h every 2h, keeping the temperature at 20 ℃ in the treatment process, and controlling the water content of the sludge to 70 wt%;

(2) after 10 days, trapping and collecting earthworms by using dry cow dung, adding straws into a material B obtained by treating the earthworms according to the weight ratio of 20: 3, then adding urea, adjusting the carbon-nitrogen ratio to 25, and then preparing a fermentation microbial agent by using bacillus natto, cellulose decomposition bacteria, bacillus megaterium, saccharomycetes and bacillus licheniformis according to the mass ratio of 1.5: 2: 1: 2: 3, wherein the number of effective live bacteria in the obtained fermentation microbial agent is more than or equal to 100 hundred million/g; adding a fermentation inoculum according to the mass ratio of the fermentation inoculum to the material B of 1: 500 for fermentation;

(3) and finishing the treatment of the domestic sludge after fermenting for 7 days, and drying the obtained material to be used as an organic fertilizer or a biological organic fertilizer.

Example 2

(1) Adding wormwood into the domestic sludge according to the weight ratio of 100: 0.5, and uniformly mixing to obtain a material A; adjusting the water content to 65 wt%, laying on a vibration table, wherein the laying thickness is 25cm, then putting 8000 earthworm seedlings into each ton of material A to treat the sludge, wherein the earthworm seedlings consist of Taiping II and Chizihessian in a quantity ratio of 2: 1, intermittently vibrating the vibration table in the treatment process, the vibration frequency is 10Hz, vibrating for 0.5h every 3h, keeping the temperature at 25 ℃ in the treatment process, and controlling the water content of the sludge to 65 wt%;

(2) after 15 days, trapping and collecting earthworms by using dry cow dung, adding straws into a material B obtained by treating the earthworms according to the weight ratio of 5: 1, then adding urea, adjusting the carbon-nitrogen ratio to be 20, and then preparing a fermentation microbial agent by using bacillus natto, cellulose decomposing bacteria, bacillus megaterium, saccharomycetes and bacillus licheniformis according to the mass ratio of 2: 1.5: 2: 3: 2, wherein the number of effective live bacteria in the obtained fermentation microbial agent is more than or equal to 100 hundred million/g; adding a fermentation inoculum according to the mass ratio of the fermentation inoculum to the material B of 1: 1000 for fermentation;

(3) after fermenting for 10 days, finishing the treatment of the domestic sludge, and drying the obtained material to be used as an organic fertilizer or a biological organic fertilizer.

Example 3

The difference from example 1 is that the earthworms in step (1) are replaced with taiping No. two alone.

Example 4

(1) Respectively placing the Taiping second earthworm seedlings and the Liriong barex earthworm seedlings on a vibration table for feeding, setting the frequency of the vibration table to be 15Hz, after the second generation earthworms are obtained by breeding, selecting the earthworms with larger individuals and more active earthworms for continuing breeding, selecting the obtained third generation earthworms according to the requirements, and repeating the steps until the sixth generation earthworms are obtained;

adding wormwood into domestic sludge according to the weight ratio of 100: 0.5, uniformly mixing to obtain a material A, adjusting the water content of the material A to 70 wt%, laying the material A on a vibration table to a thickness of 30cm, then adding 5000 seedlings of the sixth generation Taiping II and the Aisheng Gezisheng earthworm obtained by the culture into each ton of the material A, treating the material A, intermittently vibrating the vibration table in the treatment process, wherein the vibration frequency is 15Hz, vibrating for 0.5h every 2h, keeping the temperature in the treatment process at 20 ℃, and controlling the water content of the sludge to 70 wt%;

the steps (2) and (3) are the same as in example 1.

Example 5

(1) Adding wormwood into domestic sludge according to the weight ratio of 100: 0.5, drying fresh citrus peel until the water content is 40 wt%, then crushing, sieving with a 50-mesh sieve, adding the obtained powder into the domestic sludge containing wormwood according to the mass ratio of 1: 100, and uniformly stirring to obtain a material A; adjusting the water content of the sludge to 70 wt%, laying the sludge on a vibration table, wherein the laying thickness is 30cm, then throwing 10000 earthworm seedlings into each ton of material A to treat the sludge, wherein the earthworm seedlings consist of Taiping II and Chizihessian in a quantity ratio of 1: 1, intermittently vibrating the vibration table in the treatment process, the vibration frequency is 15Hz, vibrating for 0.5h every 2h, keeping the temperature at 20 ℃ in the treatment process, and controlling the water content of the sludge to 70 wt%;

the steps (2) and (3) are the same as in example 1.

Comparative example 1

The difference from example 1 is that no wormwood is added to the domestic sludge in step (1).

Comparative example 2

The difference from example 1 is that the fermentation inoculum in step (2) was replaced with EM.

Comparative example 3

The difference from example 1 is that in step (1), no vibration treatment is performed during the earthworm treatment of sludge.

Comparative example 4

The difference from example 5 is that the citrus peel in step (1) was replaced with banana peel.

Effect verification

The contents of heavy metals of cadmium, lead, chromium, mercury and arsenic in the organic fertilizers obtained in the examples 1-5 and the comparative examples 1-4 are detected, and the results are shown in table 1:

TABLE 1

As can be seen from Table 1, the heavy metal content of the organic fertilizer obtained by the method is greatly reduced compared with that of the primary activated sludge, and the organic fertilizer meets the standard requirement of the organic fertilizer on the heavy metal content.

Tomato planting tests are carried out by taking the organic fertilizer obtained in the examples 1-5 and the comparative examples 1-4 as a base fertilizer, and the specific method comprises the following steps: the test is provided with 10 treatments A to J, wherein A to I correspond to examples 1 to 5 and comparative examples 1 to 4 in sequence, J is a blank control group, each treatment is provided with 3 parallel plots, the test field is divided into 30 plots, and the area of each plot is 10m²Planting 20 tomatoes in two rows; the organic fertilizers obtained in examples 1-5 and comparative examples 1-4 were applied as base fertilizers in the A-I treatments 5 days before tomato transplantation, with the application amount of 300 kg/mu, and the J treatment was used as a blank control group without applying the base fertilizer. The land parcels are subjected to subsequent management by a conventional method, including watering and pest control. After the tomatoes were ripe, picked and weighed, the average yield of tomatoes from each treatment was calculated and the results are shown in table 2:

TABLE 2

As can be seen from Table 2, the organic fertilizer obtained by treating domestic sludge with earthworms can effectively increase the tomato yield, wherein, the comparison of the yields of the treatment A and the treatment C shows that the fertilizer efficiency of the organic fertilizer obtained by jointly treating the domestic sludge by adopting the Taiping II earthworm and the Aeschna indica earthworm is higher than that of the organic fertilizer obtained by singly adopting the Taiping II earthworm, the further verification shows that the domestic sludge is treated by singly adopting the Aeschna indica earthworm according to the method of the embodiment 1, the obtained organic fertilizer is subjected to a tomato planting test according to the method, the yield of the obtained tomatoes is not as high as that of the treatment A, because the Taiping II and the Eisenia foetida are subjected to hybrid propagation in the process of jointly treating the domestic sludge, the obtained earthworms after hybridization have stronger treatment capacity on the domestic sludge and better treatment effect on the sludge, so that the obtained organic fertilizer has higher fertilizer efficiency; as can be seen from the comparison of the yields of the treatment A and the treatment H, the vibration treatment is carried out simultaneously in the process of treating the domestic sludge by the earthworms, so that the fertilizer efficiency of the finally obtained fertilizer can be effectively improved, and because more oxygen can be blended into the sludge in the vibration process, the earthworms can better swallow and decompose the sludge; according to the yield comparison of the treatment A and the treatment D, the earthworms are subjected to vibration domestication in advance, so that the fertilizer efficiency of the obtained organic fertilizer can be effectively improved, and the earthworms can be more quickly and better adapted to the subsequent sludge treatment process through the vibration domestication, so that the treatment effect is improved; as can be seen from the comparison of the yields of the treatment A, the treatment E and the treatment I, the fertilizer efficiency of the finally obtained organic fertilizer can be improved by doping the citrus peel into the domestic sludge, but the fertilizer efficiency is not improved by doping the banana peel, which is probably because the special smell and components of the citrus peel can improve the palatability of the fermented sludge to earthworms, so that the decomposition and utilization effect of the sludge is improved, and the fertilizer efficiency of the obtained fertilizer is improved; it can be seen from the comparison of the yields of the treatment A and the treatment F, that the fertilizer efficiency of the finally obtained fertilizer can be improved by adding the wormwood into the domestic sludge, and the wormwood can keep the freshness of the domestic sludge and is more favorable for earthworms to swallow and utilize, so that the earthworms can decompose and utilize the domestic sludge more thoroughly, and the organic fertilizer with higher fertilizer efficiency can be obtained after further fermentation.

The above description is only for the preferred embodiment of the present invention, and the protection scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical scope of the present invention, the technical solution and the inventive concept of the present invention equivalent or change within the technical scope of the present invention.

Claims

1. The method for treating domestic sludge by using earthworms is characterized by comprising the following steps of:

(1) adding wormwood into the domestic sludge to obtain a material A;

2. The method according to claim 1, wherein the wormwood is added in an amount of 0.5% by weight of the sludge in the step (1).

3. The method according to claim 1, wherein the water content of the material A is adjusted to 65-70 wt% before the earthworm seedlings are put into the material A in the step (2).

4. The method according to claim 1, wherein 8000-10000 earthworm seeds are added per ton of material A in step (2).

5. The method according to claim 1, wherein the vibration treatment in step (2) is specifically: and (3) carrying out intermittent vibration treatment, wherein the vibration is carried out for 0.5 hour every 2-3 hours, and the vibration frequency is 10-15 Hz.

6. The method according to claim 1, wherein the thickness of the material A in the step (2) is 25-30 cm.

7. The method as claimed in claim 1, wherein the temperature of the earthworms in the step (2) is 20 to 25 ℃ and the treatment time is 10 to 15 days in the sludge treatment process.

8. The method according to claim 1, wherein the earthworm seedlings in the step (2) are Taiping II and/or Chiese Eisen.

9. The method as claimed in claim 1, wherein the amount of the straw added in the step (2) is 15-20% of the weight of the material B, and then urea is added to adjust the carbon-nitrogen ratio to be 20-25.

10. The method according to claim 1, wherein the fermentation microbial agent in the step (2) comprises bacillus natto, cellulose decomposition bacteria, bacillus megaterium, saccharomycetes and bacillus licheniformis according to the mass ratio of (1.5-2) to (1-2) to (2-3); the number of effective viable bacteria in the fermentation inoculum is more than or equal to 100 hundred million/g; the mass ratio of the fermentation inoculum to the material B is (1-2) to 1000; the fermentation time is 7-10 days.